#include<bits/stdc++.h>
using namespace std;
#define int long long
int read() {
  int res = 0, flg = 1;
  char c = getchar();
  while(!isdigit(c)) {
    if(c == '-') flg = 0;
    c = getchar();
  }
  while(isdigit(c)) {
    res = (res << 3) + (res << 1) + (c ^ 48);
    c = getchar();
  }
  return flg ? res : -res;
}
const int N = 1e6 + 10;
priority_queue<pair<int, string>> q;
string add(string& str, int l, int r, int x) {
  string s = str;
  for(int i = l; i <= r; ++i) {
    int c = s[i] - '0';
    c = (c + x + 10) % 10;
    s[i] = c + '0';
  }
  //cout << str << ' ' << l << ' ' << r << ' ' << x << ' ' << s << '\n';
  return s;
}
void solve() {
  while(q.size()) q.pop();
  string ori, tar;
  cin >> ori >> tar;
  q.emplace(0, ori);
  int step = 0, ans = 0;
  string cur;
  //map<string, int> ma;
  //ma[ori] = 0;
  while (!q.empty()) {
    int size = q.size();
    for (int i = 1; i <= size; i++) {
      auto p = q.top(); q.pop();
      string cur = p.second;
      int d = p.first;
      // cout << cur << '\n';
      int l = 0;
      while(l < ori.size() && cur[l] == tar[l]) ++l;
      if(l >= (int)tar.size()) {
        cout << -d << '\n'; return;
      }
      for(int r = l; r < tar.size(); ++r) {
        int k = (cur[l] - tar[l] + 10) % 10;
        if(k < 10 - k) {
          //ma[add(cur, l, r, -k)] = ma[cur] + k;
          q.emplace(d - k, add(cur, l, r, -k));
        } else {
          //ma[add(cur, l, r, 10 - k)] = ma[cur] + 10 - k;
          q.emplace(d - 10 + k, add(cur, l, r, 10 - k));
        }
      }
    }
    step++;
  }
}
signed main() {
  int t;
  t = read();
  while(t--) {
    solve();
  }
  return 0;
}